Bill Hawkins wrote: > Arrgh! Make that TWO 12.5 volt batteries. > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Bill Hawkins > Sent: Sunday, December 31, 2006 1:15 AM > To: 'Discussion of precise time and frequency measurement' > Subject: Re: [time-nuts] New pics of RFTG-m-Rb, and some comparison > details > > Ah, well. I have also received two Lucent KS-24019 L106B, aka RFTG-m-XO > boxes. The serial numbers indicate 95 and 96 construction. > The assembly numbers, 55761ASSY103902-001 (55761 is the CAGE number for > Efratom) have Rev E, S/N 522 and Rev H, S/N 2385. > > The Efratom crystal(?) oscillators are 023005-001, dated 95 and 96. > Google has no hits for that part number. > > The GPS receiver has part number 2643686MAB. This gets a few hits from > vendors that will issue a quote for anything, but will not describe the > part or its manufacturer. > > I made a power cable after tracing the male DB-9. Both drew 600 MA from > a 12.5 volt battery, started out with No GPS and Fault lights, then the > No GPS light started blinking. There was no GPS antenna on the TNC > connector, so I didn't leave them on. The antenna jack supplies +5 > volts. > > No signal appeared at the 15 MHz SMA connector, so I hope it is disabled > until the oscillator is locked. Both of their 10 MHz IN SMA connectors > still had plastic caps. > > I bought these units, and two of their RB cousins, hoping to get rid of > the HP Z3801 units and the CS standard. They add $30 monthly to the > electric bill. Now it seems that I was seriously misled, but that's the > way it goes on the net. I may yet figure out how to discipline the RB > from the XO. > > Anybody know how to divide by 2/3rds without a microprocessor? :-) > > Happy New Year (no qualifications) > Bill Hawkins > > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of David I. Emery > Sent: Saturday, December 30, 2006 11:10 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] New pics of RFTG-m-Rb, and some comparison > details > > On Sat, Dec 30, 2006 at 02:24:32PM -0500, John Ackermann N8UR wrote: > >> My RFTG-m-Rb arrived yesterday, so of course it's in pieces on the >> bench today. Photos (along with those of the -XO) are at >> http://www.febo.com/time-freq/hardware/Lucent_GPSDO/ >> > > My RFTG-m-XO arrived. > > Seems like they use a version of the UT+ timing receiver > R5122U1155, which is an 8 channel version of the Motorola Oncore design > optimized for timing. This 2002 or so version seems to have been > retrofitted to a 1996/97 base design. > > Apparently have an external antenna power supply on the > mezzanine board - presumably to allow the 80C188 to read antenna current > (or maybe it supplies 12 volts instead of 5). > > > Bill
If you mean multiply the 15MHz output by 2/3 to generate 10MHz, simply use asynchronous divide by 3 counter (2 fliplops) to produce a 5MHz 1/3 duty cycle (or 2/3) output then filter out the 10MHz 2nd harmonic component with a bandpass filter. The 3rd Harmonic (15MHz) will conveniently be very close to a null (only departure from exact 1/3 duty cycle and clock feedthrough from the divider prevent a perfect null). Bruce _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts